The present invention relates to an apparatus for testing the heat resistance, heat insulation, etc. of heat-insulating tubular members such as exhaust equipment for internal engines of automobiles. In the development of new engines, exhaust equipment attached thereto is also evaluated. For instance, the evaluation of manifolds is usually carried out by mounting them to completed engines. Accordingly, only after the completion of engines, manifolds can be evaluated, resulting in an extremely elongated period of engine development.